Bathtub



FIG. 1 is a perspective view from above of a drop-in bathtub accordingto the invention;

FIG. 2 is a top view of the bathtub of FIG. 1;

FIG. 3 is a side view of the bathtub of FIG. 1; and,

FIG. 4 is an end view of the bathtub of FIG. 1.

CLAIM The ornamental design for a bathtub, as shown and described.